The genomic tumult within tumor cells has provided scientists at Dana-Farber Cancer Institute and the Broad Institute of MIT and Harvard with clues to an entirely new class of genes that may serve as an Achilles' heel for many forms of cancer. As reported in the Aug. 17 issue of the journal Cell, the researchers identified 56 such genes, only a few of which had previously been identified as potential targets for cancer therapy. Unlike most such targets, these genes don't cause normal cells to turn cancerous. Instead, they are essential to all cells but have been disrupted as cancer progresses.